I can't put a finger on it, but this series is hitting a nerve close to home with me right now. Well written and fast paced and besides,I like bats and other under valued animals. It's also a break away from all the heavy reading subjects I normally spend my time on. There are ideas and emotions in these stories that have made me do some deep thinking besides having me glued to the story word for word. Every book in this series has one thing in common for me, I was upset at the last page that the story was over, and you can't ask any more than that out of a book.